This invention relates in general to hollow cylindrical member support apparatus and more specifically to a hollow cylindrical member supporting end flange comprising a barbed ring, a hollow cylindrical member assembly containing the end flange and methods for fabricating and using the hollow cylindrical member assembly.
A photoreceptor conventionally utilized for copiers and printers comprises a hollow electrically conductive drum substrate which has been dip coated with various coatings including at least one photoconductive coating comprising pigment particles dispersed in a film-forming binder. These drum type photoreceptors are usually supported on an electrically conductive shaft by drum supporting hubs or end flanges. The hubs are usually constructed of plastic material and have a hole through their center into which a supporting axle shaft is inserted. Since hubs are usually constructed of electrically insulating plastic material, an electrical grounding means comprising a flexible spring steel metal strip is secured to the hub and positioned to contact both the electrically conductive axle shaft and the electrically conductive metal substrate of the photoreceptor drum. One type of grounding means is illustrated in U.S. Pat. No. 4,561,763. Although excellent support is provided by these hubs, slippage between the hub and the drum substrate can occur under high torque conditions where considerable friction can be imposed on the surface of the photoreceptor by contact with subsystems such as cleaning blades and the like or where the flange on the opposite end of the photoreceptor drum is utilized to drive other copier or printer components.
Often the hub or end flange is secured to the end of the drum by a thermosetting resin adhesive. The use of an adhesive increases the number of steps and complexity of equipment required to assemble and disassemble a hub and cylindrical member assembly. Recycling of used drums having glued hubs is difficult, if not impossible, because of damage to the hub or the drum or both during removal of the hub from the drum by common techniques such as by hammering. Such removal techniques damage or destroy both the drum and the hub. Further, where disassembly is accomplished without damage, cleaning of both the hub and the cylindrical substrate is required to remove adhering adhesive. In addition, adhesive application equipment utilized during mounting of an end flange to a cylindrical substrate are difficult to maintain because the adhesive has a short pot life and often solidifies and clogs the equipment thereby requiring time consuming efforts to clean and remove the solidified adhesive. The use of bolts and nuts to secure hubs to drums requires time intensive activity.
Another type of hub avoids the need for an adhesive by utilizing resilient fingers having pointed tips that dig into and penetrate the inner surface of the drum. This hub is described in U.S. Pat. No. 5,357,321, the entire disclosure thereof being incorporated herein by reference. The hub provides excellent support for the drum. However, the pointed tips provide a limited number of gripping points to secure the hub to the periphery of a hollow drum for high torque situations. Moreover the amount of compressive pressure that can be exerted between the pointed tips and the drum is limited by the flexibility of the resilient fingers.
Thus, there is a continuing need for improved photoreceptors that are simpler to mount and remove and which can endure high torque applications.